AbstractNumerous factors that promote movement of macro-molecules in and
out of the nucleus have now been identified. These include both
soluble cytoplasmic and nucleoplasmic proteins and proteins of
the nuclear pore complex (NPC). Genetic analyses of the nuclear
transport process in the model organism, the budding yeast
Saccharomyces cerevisiae, have revealed remarkable
conservation of all of these factors. In addition, important
clues as to how these factors promote the unique bidirectional
movement across the NPC have emerged from studies of yeast. We
summarize the characterization and genetic interactions of the
soluble transport factors and present data to illustrate how
genetic experiments can be used to further define the import and
export pathways.